Collar Die Clash – Partial Collar Strike Mint Error

A collar die clash strike, aka rail road rim on reeded coins, is when the die partly strikes the top edge of the collar die. This indents that area of the die so when it strikes a coin it imparts what appears to be a double rim.

A partial collar strike is when the coin is not seated level in the coining chamber and the outside edge does not completely strike the edge.

Not to be confused with Flanning which is when metal is pushed up on the rim from the coin not being seated properly in the coining chamber or the die was tilted.